BRAND NEW w/ tags! Women's Yukon Yellow Nuclei FL size small, the perfect midlayer from Arcteryx ◡̈ Windproof, light, and packable Coreloft™ insulated hoody for climbing and other alpine pursuits. | FL: Fast and Light. Fast and light alpine travel’s static phases require thermal comfort and wind protection to offset uncomfortable conditions. Sparked by repeated athlete demand,and designed specifically by women for women, the next-generation Nuclei FL Jacket is lighter, warmer, stronger, and offers outstanding thermal performance for remarkably little weight. The Arato™ 10D fabric is windproof and alpine durable, Coreloft™ insulation is efficient and resilient, and a helmet-compatible StormHood™ gives additional warmth.